Fluid control regulators, such as gas pressure regulators are in common use in gas pipeline systems to assist in maintaining system pressure within acceptable limits. As an example, the primary function of a gas pressure regulator is to match the flow of gas through the regulator to the demand for gas placed upon the system. Also, the pressure regulator must maintain the system pressure within acceptable limits.
In one type of such gas pressure regulator, a cage is inserted between the regulator fluid input and output ports with a diaphragm assembly being under a spring load to seat against an orifice at the top of the cage. Unreliable fluid sealing has been noted occasionally in this configuration, particularly at low fluid flow conditions.
In some such prior regulators, the diaphragm assembly contains several elements of complicated structure leading to a larger than desired regulator package which also is expensive to manufacture. In other such prior regulators, the diaphragm assembly has been reduced to a minimum of components utilizing a flat plate across the top of the cage and over the orifice opening. However, in such prior regulators the orifice is not substantially open and the flow path is obstructed even when the diaphragm is in the fully opened position above the orifice, thus reducing the regulated flow through the regulator. This undesired configuration leads to lower regulator flow capacity than desired.
It is desired therefore to provide a fluid control regulator having a diaphragm assembly which accommodates a high flow capacity in a small regulator package, and contains few components so as to reduce manufacturing and assembling costs.